Fe and Cr K‐edges EXAFS Study of Double Perovskite (Sr2‐xCax)FeMoO6 (0 ≤ x ≤ 2.0) and Sr2CrMO6 (M = Mo,W) Systems |
| |
Authors: | T. S. Chan R.S. Liu L.‐Y. Jang |
| |
Abstract: | The local structure of the double perovskite (Sr2‐xCax)FeMoO6 (0 ≤ × ≤ 2.0) and Sr2CrMO6 (M = Mo, W) systems have been probed by extended X‐ray absorption fine structure (EXAFS) spectroscopy at the Fe and Cr K‐edges. We found Fe‐O (ave) distance apparently decreases from 1.999 Å (x = 0) to 1.991 Å (x = 1.0) in (Sr2‐xCax)FeMoO6 (tetragonal structure). When x is increased further from 1.5 to 2.0, the Fe‐O bond distance decreased from 2.034 Å to 2.012 Å (monoclinic structure). In addition, Cr‐O, Sr‐Cr, and Cr‐Mo bond distances in Sr2CrWO6 are all slightly larger than the bond distances of Sr2CrMoO6, which is due to the ionic radius of the W5+ (0.62 Å) which is larger than the ionic radius of Mo5+ (0.61 Å). The results are consistent with our XRD refinements data. |
| |
Keywords: | Double perovskites X‐ray absorption spectroscopy EXAFS |
|
|